Thanks. . .
So, for the TP45 I can take out 5.1 gallons before the 20/40 well pump switch kicks on, and during this time my water pressure will go from 40 to 20?
I also found
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Equation 11-2:
Vt = [(P1 + 14.7)] 15 Qp + 0.0204 D2
[P1 - P2] N
Where:
Vt = Total volume of tank in gallons
P1 , P2 = Pressures selected for system operation in psig (not absolute pressures). P1 corresponds to the pump off pressure and P2 to the pump on pressure.
N = The pump operating cycles per hour. This would either be the current recommendation of the DOH of 6 cycles per hour or a larger value when it can be justified and documented by pump or motor manufacturers' warranties.
Qp = The pump delivery capacity in gallons per minute at the midpoint of the selected pressure range. This will be determined by examination of pump curves or tables. If this value is not used, the Qp that occurs at P2 (pump on) must be used.
D = The tank diameter in inches.
MF = The multiplying factor related to tank diameter from Figure 11-1.
This is to be used only in the sizing of a horizontal tank.
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but this will take some study.